1. Field of the Invention.
This invention describes a method of producing a biodegradable insect repellant, and more particularly to a method of using natural chitinase as an insect repellant.
2. Description of the Related Art.
Worm castings have been known as being very beneficial to promote plant growth for more than 100 years but they have not been know to be effective for insect pest repellency applications. Research by Ohio State University testing for the recommended application rate of worm castings for highest growth improvement recommended a 10%-20% mix. The rule given by Ohio State University to achieve these percentages was that a xc2xd inch layer worked into the soil will provide a 10% ratio and a 1-inch layer worked into the soil will provide a 20% ratio.
U.S. Pat. No. 6,245,551 to Suslow describes a method of treating or protecting plants, fruit and roots from fungal infections comprising the step of applying an effective amount of an antibiotic-producing bacillus. Tests performed Suslow showed a systemic entrance of the chitinase-producing organisms when these were applied to the soil around the plants. Suslow did not disclose the use of chitinase as an insect repellant.
An article by Linda McGraw, New Plants Put a Hurt on Pests, published Feb. 18, 1999, describes the genetic engineering of tobacco plants by the injection of artificially produced chitinase. Plant material then consumed by insects causes the chitin of the insect to break down, making such insect subject to disease by microorganisms. The McGraw article did not describe the use of chitinase as an insect repellent.
Using worm castings to repel various insects has many advantages. Worm castings are non-toxic so provide a non-poisonous alternative to chemical pest treatments. The non-toxic nature of worm castings means the use should not harm other valuable organisms found in soil. The fact that worm castings are a natural element found in healthy soil indicates that harmful side effects should be limited. The elements found naturally in worm castings, which appear to be the active elements to repel insects, are living organisms. This means that the repellency could be provided for a longer time period unless the organisms are killed from a different source.
The present invention deals with using worm castings as an insect repellent as a layer on the ground for walking insects, incorporated into the soil feeding plants for pest insects, incorporated into the feeding liquid for hydroponic growing, and as liquid worm castings sprayed onto the leaves of plants for a topical treatment. The worm castings can be used on soil, turf, or in hydroponic applications.
It was observed that ants refused to cross a layer of worm castings. When a layer of worm castings was put around a tree or bush the reaction of the ants was immediate. Ants in the tree or bush congregate in an agitated manner just above the border of the worm castings. Soil that ants will easily cross tested at less than 1 million CFU/gdw (Colony Forming Units/gram dry weight). This supports that ants can detect and are averse to a level of chitinase somewhere between 1 and 54 million CFU/gdw. Red fire ants are particularly averse to an application of worm castings. Testing has shown that red fire ants will abandon their nests within 24 hours with a xc2xc inch application over and around the nest mound.
Testing was done on many plants to determine if worm castings are able to change the level of chitinase in the leaves of plants. This invention describes a method of using worm castings in various methods to activate the natural insect repellency produced by the chitinase-producing organisms found naturally in plants. The concentration of chitinase must be sufficiently high to repel insects. Testing has shown that the natural level of chitinase found in most plants is often not sufficient to repel insects. Worm castings are the feces or excrement from the common red earthworm found in much of the world. The genus of the red earthworm worm is eisenia foetida. Other genus of the earthworm also provide worm castings suitable for this invention. Worm castings are produced as a normal part of the worm life cycle when worms are fed a diet of various forms of biodegradable materials such as compost, paper, food waste, and any other degradable organic material. Worm castings can be used to increase the level of chitinase to a repulsion level. Liquid worm castings can be used as a foliar spray to administer a concentration of chitinase topically to the leaves and stems of plants. Liquid worm castings give a temporary repellency effect that can be effective to keep the insects away until the level of natural repellency is increased in the nectar of the plant. Worm castings can be added to soil to repel walking insects such as ants and including red fire ants. Worm castings can also be added to the hydroponic feed liquid for plants to increase natural level of chitinase production and possible other natural element to repel insects. Worm castings contain various organisms that produce enzymes known as various forms of chitinase to which insects have a strong aversion. Worm castings are called by several other names: vermi-compost, vermi-castings, worm droppings, worm manure and others. All of these terms refer to the same material.